Gold-separator.



N0. 804,400. PATENTE-D NOV. 14, 1905. P. M. JOHNSON. GOLD SEPARTOR.

APPLIOATION FILED 1m11.25, 1902.

M/ uff/V T0:

inn S'rAfrnS PATENfr' enrich.

FREDERICK M. JOHNSON, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO ROSEGOLD RECLAMATION COMPANY, OF SAN FRANCISCO, CALIFOR- NIA, A CORPORATIONOF ARIZONA TERRITORY.

GOLD-SEPRATOR.

Specification of Letters Patent.

Patented Nov. 14, 1905.

Application led March 25, 1902. Serial No. 99.909.

T0 (all 'ul/1,0m t may concern:

Be it known that I, FREDERICK M. JOHNSON, a citizen of the UnitedStates, residing at San Francisco, in the county of San Francisco andState of California, have invented certain new and useful Improvementsin Gold-Separatore, of which the following is a specification.

My invention relates to gold-saving' devices, and particularly toimprovements upon the sluice-box described in my application for patent,Serial No. 61,433, filed May 22, 1901. In that case a sluice-box isShown whose bottom has a retaining-surface composed of overlappingstrips of burlap or other Suitable material. The boX is also providedwith flexible floating aprons above the bottom composed of some similaror suitable material, the current carrying the gold-bearing sand or thecrushed or pulverized ore being compelled to pass between the two andbeing attenuated or conlined so that the heavier' and precious particlesare caught and held.

The present invention relates tothe bottom covering of the sluice and toa construction which affords a more effective retaining device than thatillustrated in the application referred to. Such construction is used incombination with the flexible floating aprons shown in the saidapplication. I have found in practice that by using such flexibleIioating aprons in connection with a bottom covering composed of fibrousor textile material and of wire screen in intimate contact betterresults are produced, and I attribute this to the resistance oropposition to the flow and to the multitude of small eddies and whirlscaused by the interstices of the screens.

The preferred construction is shown in the accompanying' drawings, inwhich" Figure l is a longitudinal section of part of sluice-boX. Fig. 2is a plan of its bottom.

The sluice-boX is ordinarily formed of wood with a bottom piece l andside pieces 2. At one end is a hopper 3, which receives the pulp, sand,pulverized ore, or other material mingled with water. Upon the bottom ofthe sluice is a retaining-surface composed of textile or fibrousmaterial and of wire screens in intimate contact. I have obtained goodresults in practice by overlaying a layer of bur lap with a successionof screens placed end to end and covering the burlap; but I prefer thefer to use.

construction shown in the drawings. The textile or fibrous material 4may be burlap, blanket, or any other suitable material, and at the headend of the sluice is laid directly upon the wooden bottom between theside pieces of the box. Upon this is placed a section of coarse-wirescreen 5. I have used quarter-inch mesh with good results. The burlap isbrought out from under the screen and then overlies another section 6 ofscreen of somewhat closer mesh, as shown, the ends of the screens comingtogether. The burlap is then covered with a third screen-section 7 ofstill closer mesh, and the arrangement contiuues to the end of thesluice, presenting alternating surfaces of burlap and wire. The screens7 and those succeeding' it need not differ in texture. rIhe burlapcovering may be a continuous strip, and this is what I pre- It is,however, perfectly practicable to use as many lengths of burlap asdesired, since the whole retaining device is firmly clamped and held inclose contact by the longitudinal cleats 8, removably secured to theboX. Above this bottom are supported flexible floating' aprons 9,substantially as shown and described in the application referred to andhaving, preferably, the waterproof upper surface or covering describedtherein.

In the operation of the separator the cur' rent or flow of materialreceived at the hopper is compelled to pass between the bottom and theaprons and is thus conlined and attenuated. The heavy and preciousparticles, whose gravity tends to deposit them, are forced down'towardthe bottom and caught. The interruption to the current caused by thescreen-meshes and aided by the downward pressure creates a multitude ofeddies and whirls, which retard the precious particles and give them abetter opportunity to deposit themselves. By placing part of the screenbeneath the burlap the latter is held slightly above the bottom. Finegold which might pass through the textile material is therefore againretarded by the screen beneath, and as the burlap is forced down by theweight of the current and the pressure of the aprons into itsinterstices a contact between such line material and the burlap isassured.

IOO

This peculiar alternating arrangement of in practice. suoli fibrous ortextile material.

Having thus fully described my invention, In testimony whereof I havealixed my sig- What I claim as new, and desire to secure by nature, inpresence of two witnesses, this 13th 5 Letters Patent, is- 1 h day ofMarch, 1902.

In a Uolc separator, a box or s nice aving.r y w a retainng-bottom composed of fibrous or tex- FREDERHJK M' JOHNSON' Vitnesses:

surfaces has been found exceedingly' eifective t layer being,alternately, suoli wire screen and tile material,in combination Withwire screens; l

arranged one above the other and in Contact, L. WT. SEELY, IO andforming two continuous layers, the upper F. M. BURT.

